Thread brake for textile machines



July 1957 w. SCHWEITER ET AL 2,799,459

THREAD BRAKE FOR TEXTILE MACHINES Filed Dec. 28, 1954 2,799,459 THREAD BRAKE FOR TEXTILE MACHINES Walter Schweitzer and Karl Marx, Horgen, Switzerland, assignors to Maschinenfabrik Schweiter AG., Horgen, Switzerland, a Swiss company The present invention relates to tension means for winding machines and more particularly, to a thread brake with at least two pairs of thread brake discs alignedly arranged to each other, whereby compression thereto is imparted by a common, spring-biased pressure distributor.

In known thread brakes a feeler controls the thread tension either before the thread enters between the brake discs or only after its delivery and exerts a counter-pressure upon the pressure distributor plate when the thread tension increases so that the braking pressure is reduced. If the feeler controls the thread running into the brake, it will respond only to relatively high tensions and it is very diflicult to keep the tension of the delivered thread constant.

If the feeler is actuated by the delivered thread, it cannot fully compensate the tension of said thread since it requires a fluctuation of tension in order to change its position. It is too mobile and can only control excess tension but cannot maintain thread tension at a constant level.

It is therefore a primary object of the present invention to obviate this disadvantage and to render the possibility of providing a feeler acting between the feed brake and the delivery brake which causes a release of the pressure distributor plate in regard to said delivery brake when thread tension rises.

Still a further object of the invention is to provide means facilitating balancing of the thread tension fluctuations in a very eflicient and greatly simplified manner by suitably influencing the action of the aforesaid pressure plate relative to the thread feed and delivery brakes.

Other objects and advantages of the invention will ensue from the description and claims with respect to an embodiment of the present invention illustrated by way of example in the attached drawing, in which:

Fig. l is an elevational view of the thread brake embodying the invention and exposing of the brake discs;

Fig. 2 is a section taken along line II in Fig. 1;

Fig. 3 is a rear view of the thread brake;

Fig. 4 is a section taken along line IIII in Fig. 3;

Fig. 5 shoWs a modified feeler;

Fig. 6 shows a further modified feeler arranged between two pairs of brake discs.

Referring now more specifically to the attached drawing there is disclosed a housing 1 provided with two bearing brackets 2 in which threaded bolts 3 which support brake discs 4 and 5 are inserted. The brake discs. 4 rest against a recessed wall of the housing 1 and the discs 5 are forced against the discs 4 by means of the pressure distributor plate 7 via rounded ends of caps 6, which, in turn, are displaceably arranged to extend over the ends of bolts 3. The pressure distributor plate 7 freely rests in slot 8 provided in projection 9 forming part of and cast on the housing 1, and is retained in position by bolt 10. Bolt 10 is provided with a recess 12. It is inserted in slot 14 of the pressure distributor plate 7 through opening 13, said slot engaging the recess 12 of StatesPatcnt ice bolt 10. Bolt 10 is therefore designed to force the pressure distributor plate 7 against the caps 6 by means of the spring 15 bearing against head 10a of the bolt 10. A rotatable knob 16 bearing the scale 16a and having an overlapping sleeve 16b is provided to set the pressure exerted by spring 15. The sleeve 16b is provided with a stepped edge 16c resting on the bolt 17 arranged on the housing 1, the spring 15 pulling the knob 16 against the housing 1. By rotating the knob 16 the tension of spring 15 and the pressure exerted on the discs may, by way of example, be adjusted by means of ten steps;

Supports 2*?) are attached to the bearing brackets 2 of the housing 1 by means of threaded bolts 3. The said supports 26 hold the shaft 21. Arranged on shaft 21 is the feeler 22 over which the thread F glides between the two pairs A and B of brake discs. Pivoted to feeler 22 is a pressure bar 23 which is guided by guide 24 and bears upon the pressure distributor plate 7 by crank action. The pressure distributor plate consists of a resilient steel plate. Provision is made through arrangement of said plate thatthe feed brakes A are less biased than the delivery brakes B. The member forcing off the pressure distributor plate is so arranged that pressure is released at the same ratio. The bolt 10 engages the pressure distributor plate below the connecting line between the points where pressure is exerted on the caps 6 and at unequal distances from the said points. The pressure lever arms are therefore of unequal length and differentiation of pressure exerted on the two pairs of brake discs is accordingly positive. Since the distance between the bolt 10 and the pressure point of the delivery brake discs B is smaller than that of the feed brake discs A, the delivery brake discs are biased more strongly, and since the points of engagement of the bar 23 and the bolt 10 are on a line 11 with the point of rest 8 of the plate 7, the feed brake discs are the first to be released by the pressure of bar 23. This causes the fluctuation of the thread tension to be balanced between the pairs of brake discs so that the feeler is moved smoothly and thereby balances the pressure constantly.

Fig. 5 shows a double-arm feeler 25 biased by the thread F at 25a and bearing against the pressure distributor plate '7 at 26.

Fig. 6 shows a modified design of the transmission of the thread tension to the pressure distributor plate in perspective view.

The shaft 30 carries a double-arm lever 31 at the two ends of which two thread guiding rollers 32 are rotatably arranged. The lever is pulled against the stop 33 by means of a counter-weight or a spring (not shown). The thread F passes from feed brake A across the two rollers 32 to the delivery brake B and forms a loop enabling its pull to be balanced, by means of which the shaft 39 is rotated. A cam 34 is arranged on shaft 30 which forces the bar 35 against the pressure distributor plate 7 by means of its rising portion 34a in a manner similar as hereinabove explained with respect to bar 23.

Having now particularly described and ascertained the nature of our said invention and in what manner the same is to be performed, we declare that what we claim is:

1. A thread brake for textile machines having at least two thread brake discs in alignment with each other and forming the feed brake and delivery brake, respectively, a common spring-biased pressure distributor plate for compressing said brakes, and a feeler arranged between said feed brake and said delivery brake and operatively connected to the pressure distributor plate for releasing same when the thread tension increases.

2. A thread brake according to claim 1, said feeler actuating said pressure distributor plate in such a manner that the two thread brakes are released to exercise different pressures.

3. A thread brake according to claim 1, said 'feeler actuating said pressure distributor plate in a direction thereagainst so that the delivery brake is more strongly released than the feed brake.

4. A thread brake according to claim 1, said feeler acting upon said pressure distributor plate in such a manner that said plate first releases the feed brake and immediately afterwards the delivery brake.

'5. A thread brake according to claim 1, including a pressure bar for actuating said pressure distributor plate which is connected with said 'feeler in such a manner that said bar is forced against said plate through crank action.

6. A thread brake according to claim 1, said feeler beingformed as a double-arm lever across one arm of which the thread passes while the other arm directly engages said pressure distributor plate for displacement.

7. A thread brake according to claim 1, said thread is passed across a swivelled double-arm lever on the pivot of which a cam is arranged which forces the pressure distributor plate into engagement.

8. A thread brake apparatus for winding and similar textile machines comprising a support, a pair of feed brake discs, a pair of delivery brake discs, said feed brake discs being arranged in spaced apart relation to said delivery brake discs on said support, whereby the thread may be guided to run from said feed brake discs to said delivery brake discs, pressure distributing means extending from said feed brake discs to said delivery brake discs and disposed on said support to abut against said feed brake discs and said delivery brake discs, means car- 4 ried by said support and maintaining said pressure distributing means in position to exert predetermined pressure against said feed brake discs and said delivery brake discs, and operable means including a thread feeler disposed intermediate said feed brake discs and said delivery brake discs and operatively connected to said pressure distributing means to actuate same in response to variations in the thread tension communicated to said feeler, to thereby vary the pressure of said pressure distributing means against said feed brake discs relative to said delivery brake discs.

9. An apparatus according to claim 8, said operable means including a pressure bar linked to and extending between said feeler and said pressure distributing means.

10. An apparatus according to claim 9, including crank means acting on said pressure distributing means and actuatable by said pressure bar, whereby said feed brake discs are released by said pressure distributing means and then said deliverybrake discs, successively.

11. An apparatus according to claim 8, wherein-said feed brake discs are adjusted to be less biased than said delivery'brake discs.

12. An apparatus according to claim 8, wherein said operable means forms a part of'said thread feeler and directly abuts against said pressure distributing means.

References Cited inthe file of this patent UNITED STATES PATENTS 1,456,074 Pigeon May 22, 1923 2,029,943 Reiners et a1. Feb. 4, 1936 2,080,893 Klein May 18, 1937 2,629,561 Heizer Feb. 24, 1953 

